The present invention relates to a method for measuring velocity and direction of currents in bodies of water, such as an ocean, and more particularly to a method for making and recording a plurality of readings of current velocity and direction at various depths.
Oceanographic instruments for sensing and indicating velocity components and current flows are generally of a moored or fixed type or of a traveling type. Although the more commonly type is of the moored or fixed type, the main disadvantage is that readings are obtained for only one depth and it is usually desirable to know current velocities at a plurality of depths.
One such fixed device for measuring current flows is shown and described in U.S. Pat. No. 3,695,103, which issued Oct. 3, 1972, to Franklyn C. W. Olson. In this device, a buoyant sphere is anchored at a desired depth by a trio of taught wires containing strain gages. The outputs of the strain gages, which is affected by the direction and magnitude of the current, are fed into a computer which converts the readings into a resultant velocity and direction of current flow.
In U.S. Pat. No. 3,623,362, which issued Nov. 30, 1971, to Robert D. Gerard, there is shown and described a current measuring device for recording current during the free fall and rise of an instrument. Direction is obtained by taking readings from a magnetic compass and current velocity is determined by four transducers which are mounted, two each, on the ends of two probes, which are rotated in the water being checked.